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authorMichel Dänzer <michel@daenzer.net>2006-09-28 14:03:02 +0000
committerMichel Dänzer <michel@daenzer.net>2006-09-28 14:03:02 +0000
commit6a2f5c6752213cea67b142727eba9e0900952346 (patch)
tree05784d009260b90376056f1114707af7bdf13c01 /src/mesa/drivers/dri/common
parent24bb3b399847bdb11f0008820c2c1bad1e21d499 (diff)
Some restructuring of the driWaitForVBlank() code.
Also some minor fixes for detecting when the deadline is met or missed, in particular wrt wraparounds of the sequence number.
Diffstat (limited to 'src/mesa/drivers/dri/common')
-rw-r--r--src/mesa/drivers/dri/common/vblank.c50
1 files changed, 27 insertions, 23 deletions
diff --git a/src/mesa/drivers/dri/common/vblank.c b/src/mesa/drivers/dri/common/vblank.c
index 25b912e824..c7c7b8296e 100644
--- a/src/mesa/drivers/dri/common/vblank.c
+++ b/src/mesa/drivers/dri/common/vblank.c
@@ -260,7 +260,8 @@ void driDrawableInitVBlank( __DRIdrawablePrivate *priv, GLuint flags,
drmVBlank vbl = { .request={ .type = DRM_VBLANK_RELATIVE, .sequence = 0 } };
do_wait( &vbl, vbl_seq, priv->driScreenPriv->fd );
- priv->pdraw->swap_interval = (flags & VBLANK_FLAG_THROTTLE) != 0 ? 1 : 0;
+ priv->pdraw->swap_interval = (flags & (VBLANK_FLAG_THROTTLE |
+ VBLANK_FLAG_SYNC)) != 0 ? 1 : 0;
}
}
@@ -287,7 +288,7 @@ driWaitForVBlank( const __DRIdrawablePrivate *priv, GLuint * vbl_seq,
unsigned original_seq;
unsigned deadline;
unsigned interval;
-
+ unsigned diff;
*missed_deadline = GL_FALSE;
if ( (flags & (VBLANK_FLAG_INTERVAL |
@@ -310,43 +311,46 @@ driWaitForVBlank( const __DRIdrawablePrivate *priv, GLuint * vbl_seq,
original_seq = *vbl_seq;
- vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0;
- vbl.request.type = DRM_VBLANK_RELATIVE;
-
- if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
- return -1;
- }
-
-
- vbl.request.type = DRM_VBLANK_ABSOLUTE;
-
if ( (flags & VBLANK_FLAG_INTERVAL) != 0 ) {
interval = priv->pdraw->swap_interval;
/* this must have been initialized when the drawable was first bound
* to a direct rendering context. */
assert ( interval != (unsigned)-1 );
}
- else if ( (flags & VBLANK_FLAG_THROTTLE) != 0 ) {
+ else if ( (flags & (VBLANK_FLAG_THROTTLE | VBLANK_FLAG_SYNC)) != 0 ) {
interval = 1;
}
else {
interval = 0;
}
+ deadline = original_seq + interval;
- /* Wait until the next vertical blank. If the interval is zero, then
- * the deadline is one vertical blank after the previous wait.
- */
+ vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0;
+ vbl.request.type = DRM_VBLANK_RELATIVE;
+
+ if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
+ return -1;
+ }
- vbl.request.sequence = original_seq + interval;
- if ( *vbl_seq < vbl.request.sequence ) {
- if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
- return -1;
- }
+ diff = *vbl_seq - deadline;
+
+ /* No need to wait again if we've already reached the target */
+ if (diff <= (1 << 23)) {
+ *missed_deadline = (flags & VBLANK_FLAG_SYNC) ? (diff > 0) : GL_TRUE;
+ return 0;
+ }
+
+ /* Wait until the target vertical blank. */
+ vbl.request.type = DRM_VBLANK_ABSOLUTE;
+ vbl.request.sequence = deadline;
+
+ if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
+ return -1;
}
- deadline = original_seq + ((interval == 0) ? 1 : interval);
- *missed_deadline = ( *vbl_seq > deadline );
+ diff = *vbl_seq - deadline;
+ *missed_deadline = diff > 0 && diff <= (1 << 23);
return 0;
}